The processing of sugar to produce refined sugar can include several steps, for example, an evaporation step followed by a crystallization process. During an evaporation step, sugar liquor may be concentrated to sugar syrup. Sugar crystals may also evaporate out of solution. The sugar syrup may then be sent to crystallizers for further processing to produce sugar crystals. The resulting mixture from the crystallization step is called massecuite, which may be composed of sugar crystals in a thick, viscous liquid (molasses). The massecuite may also contain dissolved sugar and organic and inorganic impurities. To isolate the sugar crystals, the massecuite may be processed through a centrifuge to separate the sugar crystals from the liquid molasses.
During centrifuge processing, the efficiency and speed of separating the liquid molasses from the solid sugar crystals can be dependent, in part, upon the viscosity of the continuous liquid phase massecuite. Highly viscous massecuite can impede the release of the liquid molasses from the crystals during centrifugation. Viscosity reduction may not necessarily be easily accomplished because the crystals are in equilibrium with the liquid phase and any change by, for example, dilution or temperature may cause the crystals to dissolve.
There are devices available to increase the flowability of the massecuite in large mixers and heat exchangers, but because these devices are so far upstream of the centrifuge processing step, these devices may not provide as thorough viscosity reduction as desired because of the risk of dissolving crystals as mentioned above. Several pre-conditioning systems have been developed over the years including, for example, the Steven Coil by Western States, but these devices are generally reserved for heating the massecuite and agitating the massecuite to facilitate an even distribution of heat transfer. These heated mixers can be very large, and are piped between the crystallizers and centrifuges, and can have very long-residence times.